free hit
counters
Battery light on - Page 2 - Engine/Ancilliaries - The Lotus Forums Jump to content
Glyn Harper

Battery light on

Recommended Posts

Thanks Jacques.

I’m actually away at the moment, back home tomorrow, so I haven’t had a chance to touch the car. The alternator supplier in the US did send the two spare regulators though, true to their word, and they arrived just before I left to go on holiday. So I’ll swap one of those out when I get back.

My plan is to remove the box part of the plenum chamber to gain access to the regulator, as this should only take a few minutes, whereas removing and replacing the alternator is a couple of hours and lots of cuts on the arms from the poor access to the bolts. I’ve got a new plenum chamber gasket sat waiting. :)

The alternator I have is apparently the same type that was fitted to Mercedes in the 1980’s, but fully rebuilt. It was like new when it arrived so I’m hoping it’s just a faulty component on the brush unit.

It’s had about 200 miles to bed in probably, but it’s the way it suddenly started working when the car got down to about 12v that makes me think the regulator is bad. Not sure what the flat electronic component on the back of it is, but I think it’s that that’s failed. Really hope it’s not melted like yours!

Here is a stock picture from the original eBay add (not my car) showing the same alternator in situe on someone else’s Esprit.

They say they’ve sold loads to Esprit owners with no issue, and have loads of 100% good feedback going back years, and they have seen me right with new regulators. I guess I just had an unlucky one. :)

 

8F1AC996-97D7-4CF5-BB4E-773DA46B454A.jpeg

Edited by Glyn Harper

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

So, fitted a new voltage regulator today. My trick of taking the plenum chamber off rather than the alternator worked a treat! Sooo much easier taking the plenum off, even factoring in cleaning off the old gasket. Also, gave me a chance to make sure there were no nasty surprises in the plenum chamber as well (Oil and/or charge cooler coolant!!)

Started the car, didn't charge! But as has been said, it may have taken the new brushes some time to bed in. So I put a load of lights and electrical items on, revved the engine and it started charging.

Turned everything off, stopped the engine, left the car 10 minutes and tried again with just the engine running. (No load). The battery light was still on, but then I revved the engine slightly and it started charging.

So, it's kind of working ok now. Guess the regulator was a bit faulty. Still a little odd that I had to rev it to get it charging again, but I've a feeling it was like that all along! Odd cars. :)

  • Like 1

Share this post


Link to post
Share on other sites

Glyn,

I don't think it's supposed to be like that. I'll take a Measurement on my 90' SE in ½ hour and post here (have to go an d pick up the car).

Kind regards,

Jacques


Nobody does it better - than Lotus ;)

Share this post


Link to post
Share on other sites

At Idle, 950-1000 rpm, I measure 14,37 Volt steady at the voltage regulator. Battery terminal is 13,97 Volt. It's the original Generator, but a new voltage regulator. Car's done 119.000km.

Hope it's of any use.

Kind regards,

Jacques


Nobody does it better - than Lotus ;)

Share this post


Link to post
Share on other sites

The pulley on my new alternator is slightly bigger. I had to use a belt that was about 2cm longer than standard. Wonder if that’s causing it not to kick in until I rev it initially. 

 

Share this post


Link to post
Share on other sites

that was my thought also Glyn, bigger pulley means lower RPM. I also had to fit a longer belt on my engine with the AL49X alternator. (still not finished and not running yet).

Once we know the pulley dimensions we might have an explanation / cure for the problem.


Esprit Freak

Share this post


Link to post
Share on other sites

Will do, but I just put the car away, not going there till' Tuesday.

As I see it, using a larger pulley on the alternator, makes a lower gearing on that mening, that the alternator will turn slower on a given engine rpm, which in turn will make the alternator make less output. I think this is the cause.

Kind regards,

Jacques


Nobody does it better - than Lotus ;)

Share this post


Link to post
Share on other sites

May be it then. The output on mine (when it kicks in) seems to be about 13.6v, which although a little lower, is plenty enough.

Guess I’ll just have to use it for a while without cheating with my trickle charger, and see how it behaves.

Share this post


Link to post
Share on other sites

When I changed to the Bosch AL49X, I put the original Lotus pulley on it. 

Ample charging capability at all speeds (even at idle).


Atwell Haines

'88 Esprit

Succasunna, NJ USA

Share this post


Link to post
Share on other sites

Actually, I remember now I did actually change to the original pulley! The reason the belt is about 2cm longer is because the body of the new alternator is slightly larger than the original, so the pulley is just 1cm further away which accounts for the extra 2cm on belt length. So maybe it just needs bedding in a little. It's working though, just odd you have to rev it from cold to get it to kick in.

Looking on google at images, it does appear my new one is indeed a Bosch AL49X as well. We probably got them from the same guy as it came from the USA. :)

Share this post


Link to post
Share on other sites

After a year's use with my AL49X, I started to get low charging initially, and at all RPMs.   No noise or squealing.

 

Had the system checked out at an auto electric shop. They said its wave-form was OK and it was putting out 70 amperes under load (rated at 90).

 

Turned out, the belt simply wasn't driving the alternator very well!   Another new belt, and more UMPH with the tensioning crow-bar, 😉 💪 and its been fine for 6,000 miles.

 

In light of your 'confession', I'd go back to the OEM size belt (make sure the width is correct, too) and verify it is tight enough.  (Yes, it can be a b**ch to properly tension!) The Bosch should fit fine, IIRC the overall size is the same (it's only the lower 'ear' that is different).

 

PS, my AL49X was a factory reconditioned unit from Bosch, purchased from Rock Auto in the USA.


Atwell Haines

'88 Esprit

Succasunna, NJ USA

Share this post


Link to post
Share on other sites

When I first fitted it, the belt wasn't tensioned properly for sure. I have electric power steering, and when steering at low speeds the belt would squeal sometimes.

So I ended up using a handy quick clamps thing, with the clamps set to push outwards (like this one) and I was able to use that to put some tension on the alternator and then tighten the bolts. Worked a treat!

The standard belt definitely wouldn't go on though, which is why I went the next size up which was 2cm longer. It fits perfectly and it is tensioned correctly. I'm wondering now that the regulator has changed, it just needs the bushes bedding in slightly.

Just need to put some miles on it really. I'm going to try and get it out this Thursday and Friday actually, the weather is still meant to be good.

 

s-l300.jpg

Edited by Glyn Harper

Share this post


Link to post
Share on other sites

It seems fine. When I first start the car, the battery light initially is on. If I gently rev it, the light goes off and it charges. When it drops down to idle, the battery light doesn't come on, it stays charging. So it seems to just be that initial first time after it's switched on as if it's initially 'sticky' and then works ok.

Share this post


Link to post
Share on other sites

Your '88 has a voltage gauge, correct?

Re-state your previous post, but tell us the indicated voltage under the same conditions.

 

My AL49X equipped car indicates 12.5V at key-on, engine off.  Soon as the engine 'catches', (cold idle ~ 1900 RPM), the voltage gauge indicates almost 14VDC (perhaps, one needle-width less). After 20 minutes of daytime driving, the indicated voltage is about 13.3 - 13.5V (telling me that the battery has been recharged). This voltage is the same even at the warm idle speed of 950 - 1000 RPM.


Atwell Haines

'88 Esprit

Succasunna, NJ USA

Share this post


Link to post
Share on other sites
On ‎10‎/‎06‎/‎2018 at 16:55, fjmuurling said:

Hi Jacques, @Jacques

can you measure the diameter of the pulley on your original alternator ?

@Jacques or @Glyn Harper,

can you still measure the diameter of the alternator pulley? I would like to check if I have the right one. (former alternator was not an original one).


Esprit Freak

Share this post


Link to post
Share on other sites
22 hours ago, CarBuff said:

Your '88 has a voltage gauge, correct?

Re-state your previous post, but tell us the indicated voltage under the same conditions.

 

My AL49X equipped car indicates 12.5V at key-on, engine off.  Soon as the engine 'catches', (cold idle ~ 1900 RPM), the voltage gauge indicates almost 14VDC (perhaps, one needle-width less). After 20 minutes of daytime driving, the indicated voltage is about 13.3 - 13.5V (telling me that the battery has been recharged). This voltage is the same even at the warm idle speed of 950 - 1000 RPM.

I’ve retrofitted the 96 interior with fewer gauges, so I’ve lost the battery gauge.

having said that, I’ve just realised that as I have a Pioneer Avg-vdp1 I can actually use that to show me the battery voltage.

My cold idle is about 1,000 rpm (I don’t have a throttle jacking solenoid or air bypass) so I’m pretty convinced now it starts charging after an initial rev which sort of wakes it up.

will investigate tomorrow.. as well as measure my alternator pulley for Freek. :)

Edited by Glyn Harper

Share this post


Link to post
Share on other sites

Sorry to hear you 'upgraded', LOL.

 

 

There is always this work-around:

https://www.amazon.com/Charger-Display-Voltage-Current-Samsung/dp/B01LY6JEBQ

image.png.a5007824b73b7aef632042ecc01896ae.png

That way your phone can remained charged so that you can call the Auto Club. 😁

 

  • Like 1

Atwell Haines

'88 Esprit

Succasunna, NJ USA

Share this post


Link to post
Share on other sites

I actually ordered one of those a couple of days back, then realised I can display voltage on my stereo. :)

at least I’ll be able to check they’re both the same reading. 

Share this post


Link to post
Share on other sites

Curses. Took it for a drive this evening and everything was fine. Charging quite happily. Then all of a sudden, the battery light comes on and the voltage on my headhunt shows 11.5v (actually about 12.4v at the battery when I checked it when I got back).

So it's stopped charging properly again. Checked the belt, that's fine and it's not slipping. Changed the voltage regulator last week and it's not cured it so it's not that.

Checked the alternator body is earthing well and it is. Even tried an earth directly between the body and the battery - post last week so it's not that.

Anything else it could be? Apart from the voltage regulator/brushes (which are one replaceable unit) I didn't think there was much else could go wrong with an alternator is there?

Going to try it again tomorrow to see if it starts charging again when the voltage drops even more. Deliberately not put it on the trickle charger tonight.

 

Share this post


Link to post
Share on other sites

Still got the wrong size pulley on the alternator?


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

Share this post


Link to post
Share on other sites
18 minutes ago, Sparky said:

Still got the wrong size pulley on the alternator?

I'll measure it tomorrow, but I'm pretty sure it's the correct one. The extra belt length is because the alternator is slightly wider than the original one, so the pulley centre is actually about 1cm further away from the crank than it was on the original alternator, although the pulley is the same diameter.

I'm going to try and give all the earths and leads a really good clean up tomorrow and see if that helps.

It's funny how it was working fine, then just stopped. I bet when the charge drops it'll start working again though. It's odd.

Edited by Glyn Harper

Share this post


Link to post
Share on other sites

* Sorry for asking, but is there any chance that your alternator charges fine (let's say), and that the battery error tell tale have it's own fault?

You can verify that by measuring directly with wires on the alternator along the car into the drivers position to monitor a fluke or similar while driving.

* another thing is brokes wires under the insulation (or badly corroded). I've seen that on other cars (not Lotus). Make up some new charging and earth wires in nice fat correctly made type and connectors.

* Is you battery okay? Is it defect in a terminal? (like in broken or disconnected internally).

Just saying.

Kind regards,

Jacques


Nobody does it better - than Lotus ;)

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...